Linear lamp replacement

ABSTRACT

A linear lamp is provided having one or more light emitting elements provided therein. The light emitting elements are directed to emit light in a direction different from the primary direction of the illumination of the lamp. The light emitting elements may be supported by a supporting optical element. The supporting optical element may permit the transmission of light therethrough. The supporting optical element may be an integral window upon which the light emitting elements are disposed.

CROSS-REFERENCE

This application claims the benefit of U.S. Provisional Application No.61/896,491 filed Oct. 28, 2013 and U.S. Provisional Application No.61/903,339 filed Nov. 12, 2013, which applications are incorporatedherein by reference in their entirety.

BACKGROUND OF THE INVENTION

Currently, many lighting systems use fluorescent tubes to provideillumination. Fluorescent tubes have lifetimes limited by on/off cycles,a 360 degree light distribution that is not optimal (half goes into theroom, half goes toward the ceiling), limited efficacy, and containsmercury. Light emitting diode (LED) solutions can solve many of thechallenges faced by fluorescent tubes. However, a common problem withLED solutions is a non-optimal compromise between efficiency and glare.To control glare the common approach is to use a diffuser which can beinefficient. Efficient solutions often orient the LED in direct line ofsight to the work surface causing eye discomfort from bright spots oflight.

Thus, improved lighting solutions are needed, which can be used toreplace fluorescent tube lighting systems.

SUMMARY OF INVENTION

Aspects of the invention are directed to a light source made up of lightemitting elements attached to a PCB or flex circuit and in contact witha support structure and heat dissipating element, and directed toward atleast one partially reflecting reflector and away from the primarydirection of the intended illumination. Orienting the LEDs directlyopposite the work surface can reduce glare and can reduce or minimizethe number of light bounces before exiting the lamp in the direction ofthe work surface.

The light emitting elements may include one, two or more colors or colortemperatures. The support structure can also be an optical element. Theheat dissipating element may also be an optical element. Thecross-sectional width of the light source may be elliptical-like. Thecross-sectional width of the light source can have two distinct widthsthe larger of the two improves optical efficiency and the smaller of thetwo provides mechanical and electrical compatibility with T8 sizefluorescent lamps or other lamp sizes between T50 and T5.

An aspect of the invention is directed to a lamp comprising: one or morelight emitting elements emitting light primarily in a direction that isdifferent from a primary direction of illumination of the lamp; acircuit board upon which the one or more light emitting elements aredisposed; and a supporting optical element formed from an at leastpartially optically transmissive material supporting the circuit board.In some embodiments, light emitting elements (e.g., light-emitting diode(LED) packages, LED chips) can be mounted directly on the supportingoptical element, which may be a transparent material such as glass orplastic, that can become a circuit board with the inclusion ofconductive interconnects such as indium tin oxide (ITO), metals such ascopper, or any conductive material suitable for the power requirementsof the application.

Additional aspects and advantages of the present disclosure will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein only exemplary embodiments of the presentdisclosure are shown and described, simply by way of illustration of thebest mode contemplated for carrying out the present disclosure. As willbe realized, the present disclosure is capable of other and differentembodiments, and its several details are capable of modifications invarious obvious respects, all without departing from the disclosure.Accordingly, the drawings and description are to be regarded asillustrative in nature, and not as restrictive.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 shows a high level schematic of a lamp, in accordance with anembodiment of the invention.

FIG. 2 shows a cross-section of a lamp, in accordance with an embodimentof the invention.

FIGS. 3A-3B shows a light emitting element and supporting structure inaccordance with an embodiment of the invention.

DETAILED DESCRIPTION OF INVENTION

The invention provides systems and methods for providing illumination. Alinear replacement light may be provided to replace fluorescent tubes.Various aspects of the invention described herein may be applied to anyof the particular applications set forth below or for any other types oflighting configurations. The invention may be applied as a standalonedevice or method, or as part of an integrated lighting system. It shallbe understood that different aspects of the invention can be appreciatedindividually, collectively, or in combination with each other.

An efficient light source can be desirable for mass adoption in anindustrial society. Beyond energy efficiency there are numerous othercharacteristics that can be desirable in a light source. Descriptionsprovided elsewhere herein provide examples of desirable characteristics,which are not limiting or exhaustive.

It can be generally desirable to have control over the distribution ofoptical radiation out of a light source. One or more light emittingelements may be provided as a light source. Most light emitting elementsincluding semiconductor light sources, such as light emitting elements(LEDs), which have an isotropic emission at their genesis. One type oflight emitting element which does not have isotropic emission is a laserwhich has nearly perfect collimation. In many lighting applications,some light distribution other than isotropic light distribution can bedesired, although different applications may call for differentdistributions. In the case of a ceiling mounted luminaire such as atroffer, a primary goal can be to illuminate a work surface such as adesk or table below. Light distribution up toward the ceiling is mostlywasted and cuts into the energy efficiency of a light source. Thus, itmay be preferable to use other light distribution arrangements toindirectly illuminate a work surface. Other distributions could includea wall wash application where an asymmetric pattern is desired toilluminate the vertical surface evenly. Another example is a suspendedpendant which may also have an asymmetric distribution that sends aportion of the light down and a portion of the light up to partiallyilluminate the ceiling for aesthetic reasons. Direct side to sideemission can result in wasted energy. There are many potentialdistributions that will need different optical elements or tools toshape the light from its isotropic origins to the desired distributionfor the application. Additionally there is often a desire to minimizeglare when the light source or light emitting elements are vieweddirectly or in any manner that allows high density light to enter theeye from any angle. Oftentimes, increased degrees of shaping and glaremitigation can result in a lower efficiency of the optical system.

FIG. 1 shows a high level schematic of a lamp 100, in accordance with anembodiment of the invention. The lamp may be configured to function as afluorescent tube replacement. The lamp may be used to retrofit anexisting fluorescent lighting unit. The lamp may include a body 110 andone, two, or more end caps 120. In some embodiments, the lamp may notinclude a power supply or a complete optical system that defines thefinal light distribution into an environment (e.g., room), or may notcontain the complete mechanical structure to allow it to attach to astructure (e.g., room, building) in contrast with a luminaire. In someembodiments, a lamp may be smaller than a luminaire, which may have apower supply or ballast, final optics, and mechanical structure toattach to the structure (e.g., room, building). In some otherembodiments, the lamp may be a self-ballasted lamp, such as compactfluorescent or LED, or some lamps may be used in configurations that donot require additional optics. In additional embodiments, lamps may beprovided without a fixed mechanical structure (e.g., MR16 lamps) thatcan be hung from wires tensioned across some distance to provide ad hocmechanical support and electrical connection. In some embodiments,luminaires provide a more complete package as a lighting fixture than alamp. Lamps may include a pin, screw base, or other male electricalconnections that may fit into a socket, while a luminaire may beconnected directly to a mains electrical wiring or wall plug. Anydescription herein of a lamp may also apply to a luminaire.

In one example, the body 110 may be an elongated body. The lamp may be alinear lamp and/or have a linear configuration. The body length to widthratio may be greater than, less than, or equal to about 500:1, 300:1,200:1, 100:1, 90:1, 80:1, 70:1, 60:1, 50:1, 40:1, 30:1, 20:1, 10:1, 8:1,7:1, 6:1, 5:1, 4:1, 3:1, 2:1. The body length may be greater than, lessthan, or equal to about 3 inches, 6 inches, 9 inches, 1 foot, 18 inches,2 feet, 30 inches, 3 feet, 42 inches, 4 feet, 5 feet, 6 feet, 7 feet, 8feet, 10 feet, 15 feet, or any other length. The elongated body mayinclude an optical system which may include one or more opticalelements. In some embodiments, the optical system may include a window.The optical system may also include reflector, or other optical elementas discussed elsewhere herein.

The elongated body may have any shape. In some embodiments, theelongated body may have a semi-cylindrical shape (e.g., with one curvedside and one flat site). In other embodiments, the elongated body mayhave a cylindrical or prismatic shape. In some embodiments, the bodysides may be exposed to ambient air. In one example, the flat side andthe curved side of a body may be exposed to ambient air. The sides ofthe body may be exposed without requiring any fins or protrusions on theexterior of the body. Extra external heat dissipating mechanisms may notbe required on the body.

The body 110 may have one or more light emitting elements 115. The lightemitting elements may have any configuration. For example, the lightemitting elements may form one row, two rows, three rows, or more rows,extending along the length of the elongated body. The light emittingelements may form an array or staggered rows. The light emittingelements may have a circular, curved pattern, or other arrangementssuitable for the application. The light emitting elements may or may notbe evenly spaced apart from one another. In some instances, the lightemitting elements may be spaced apart from one another by a distancegreater than, less than, or equal to about 1 mm, 3 mm, 5 mm, 7 mm, 1 cm,1.2 cm, 1.5 cm, 1.7 cm, 2 cm, 2.5 cm, 3 cm, 4 cm, 5 cm, 7 cm, or 10 cm.In some instances, the distance between the light emitting elements mayfall between two of the distances described herein. The light emittingelements may be spaced sufficiently far apart to permit heat generatedby the light emitting elements to substantially dissipate.

In some instances, the light emitting elements 115 may have a primarydirection of illumination. For example, the light emitting elements maybe LEDs that are directed in a primary direction. For example, relativeto a fixed reference frame, the LEDs may be directed upwards (positive Zdirection). The LEDs may be top-emitting LEDs. The primary direction ofillumination for the light emitting elements may optionally be differentfrom the primary direction of illumination of the lamp 100. In oneexample, relative to the fixed reference frame, the lamp may beprimarily directing illumination downwards (negative Z direction). Thelight emitting elements may primarily direct light in a directionopposite the primary direction of illumination of the lamp.Alternatively, the light emitting elements may direct light in adifferent direction relative to the primary direction of illumination ofthe lamp (e.g., at an angle greater than, less than, or equal to 15degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees, 90 degrees, 105degrees, 120 degrees, 135 degrees, 150 degrees, 165 degrees, 180degrees). In some embodiments, the fixed reference frame may correspondto a surface of the environment being illuminated (e.g., Z axis may besubstantially orthogonal to a ground, floor, wall, structure, ceiling,ramp, surface). The fixed reference frame reference frame may correspondto the direction of the Earth's gravity (e.g., Z axis may besubstantially parallel to the direction of gravity, positive Z directionopposing gravity).

In some instances, the light emitting elements 115 may be partially orcompletely enclosed within the body 110. The light emitting elements maybe surrounded by one or more optical elements. The light emittingelements may be supported by an optical element, such as a window. Insome instances, one or more of the optical elements may permit theillumination from the light emitting elements to be redirected to theprimary direction of illumination of the lamp 100.

The lamp 100 may include one or more end caps 120 connected to the lampbody 110. The end caps may be mechanically connected to the lamp body.The end caps may be electrically connected to one or more light emittingelements 115. In some instances, the lamp may have two ends, with endcaps at each end. The end caps may be at opposing ends of a linearelongated body. In alternative embodiments, the body may be bent,curved, form a U-shape, form a circular shape, branch off intoadditional ends, form a cross-shape, or any other shape. Any number ofend caps may be selected to correspond to the number of ends of providedby the lamp body. The end caps may be configured to mechanically and/orelectrically couple the lamp 100 to a conventional fluorescent lightreceptacle, or any other type of light receptacle. Alternatively,coupling can be achieved without end caps.

The end caps 120 may include one, two or more electrical connectors 125,such as pins, which may permit the lamp to be engaged in a lightingsystem. Coupling may be achieved, for example, through the use ofconductive pins protruding from the end caps, as is used in conventionalfluorescent light tube to receptacle coupling schemes. The electricalconnectors may or may not be formed from an electrically conductivematerial. For example, two pins may be provided per end cap. The pinsmay or may not be parallel. In one embodiment, at least one of the endcaps may be used only for mechanical coupling. Alternatively, otherelectrical connection mechanisms may be utilized. A lighting unit may beslid and/or twisted into a fixture. A lighting unit may be removablyattached to a lighting fixture. Alternatively, the lighting unit is notremovable from the lighting fixture.

To increase or maximize efficiency, an optical system can be designed tominimize or reduce the number of photon bounces from a light emittingelement to exiting the light source. After reducing or minimizing thenumber of bounces, the surfaces redirecting the light can be of the bestquality (e.g., highest or increased reflectivity or transmission) thatcan be economically applied for a given application. In general theoptical tools or elements available include reflectors (e.g., includingdiffuse and specular), refractors (e.g., lenses including imaging,non-imaging, and Fresnel), diffractors (e.g., including gratings andnano patterns), diffusers (e.g., including bulk and surface), filters(e.g., including high pass, low pass, and notch), and/or light guides(e.g., including flat and curved). A special case of an optical elementis a clear window or transparent cover. A window can be “optical” inthat it passes visible radiation with little attenuation but does nothave optically transformative properties, commonly referred to assecondary optics, that the other aforementioned optical elements have.Optical surfaces may or may not have anti reflective coatings toincrease efficiency. These tools or elements can be used alone or in anycombination to optimize or improve the performance and cost of thedesign for the application.

Light emitting elements may produce waste heat to be managed. In thecase of vacuum light sources, this waste heat can be mostly radiatedaway. In the case of solid state light sources, the heat can be mostlyconducted away. As solid state light sources are increasingly used inluminaires that were designed for vacuum light sources, one heatmanagement technique may be to first conduct and then radiate or convectthe waste heat safely away. Important considerations are the density ofthe heat source, the number of interfaces, the thermal resistancesbetween the light emitting element and the ambient environment, and thesurface area of the structure in contact with the ambient environment. Asmall reflector lamp such as an MR16 has a much higher heat sourcedensity than a four foot linear lamp such as a T8. The followingexamples are for low heat density linear applications in the range of aT5 to a T50 but should not be considered exclusive of other shapesincluding high heat density reflector sources. It can be advantageous,in terms of efficiency and/or cost, to reduce or minimize the number ofinterfaces between light emitting element and ambient environment, andthen minimize the thermal resistance of each interface. Air gaps andvoids in the thermal path can be avoided as is economically practical.

FIG. 2 shows a cross-section of a lamp 200, in accordance with anembodiment of the invention. The lamp may include one or more lightemitting elements 210 that may be provided on a circuit board 220. Thelight emitting element and/or circuit board may be supported by asupporting optical element, such as a window 230. A redirecting opticalelement 240 may be provided which may redirect or modify the light fromthe light emitting element. In some embodiments, an internal space 250may be provided within the lamp. A secondary internal space 260 may alsobe provided.

The lamp 200 may include one or more light emitting elements 210. Thelight emitting elements may be any illumination source known in the art.For example, the light emitting elements may include a light emittingdiode (LED). A light emitting element may include an LED package. Alight emitting element may or may not be a phosphor converted LED. Thelight emitting element may comprise an LED chip and an encapsulantand/or other lenses or reflectors that function as a primary optics. Insome embodiments, a light emitting element may comprise a phosphorproximate to the LED chip configured to convert a portion of the lightemitted by the LED chip to a longer wavelength. Alternatively, the lightemitting element need not have a phosphor coated thereon. A lightemitting element can be formed of a semiconductor material with aprimary optic. In some embodiments, a light emitting element may be apoint source or substantially point source light emitting element. Thelight emitting element may provide isotropic light.

In some embodiments, a light emitting element may be a top emitting LED.In other embodiments, a light emitting element may be a side emittingLED or a bottom emitting LED. The light emitting element may directlight in any or multiple directions. In some instances, the lightemitting element may have a primary direction of illumination. Forexample, the primary direction of illumination of a top emitting LED maybe the direction of the top face of the LED. Even if light is emittedisotropically, a body or other portion of the light emitting element mayblock the light in certain directions, so that the light may have aprimary direction of illumination.

In alternative embodiments, the light emitting elements may be coldcathode fluorescent lamps (CCFLs) or electroluminescent devices (ELdevices). Cold cathode fluorescent lamps may be of the type used forbacklighting liquid crystal displays and are described generally inHenry A. Miller, Cold Cathode Fluorescent Lighting, Chemical PublishingCo. (1949) and Shunsuke Kobayashi, LCD Backlights (Wiley Series inDisplay Technology), Wiley (Jun. 15, 2009), which are herebyincorporated by reference in their entirety. EL devices include highfield EL devices, conventional inorganic semiconductor diode devicessuch as LEDs, or laser diodes, or solid state devices with radiationpatterns in between an LED and laser diode such as those that may employa resonant cavity or photonic lattice, as well as OLEDs (with or withouta dopant in the active layer). A dopant refers to a dopant atom(generally a metal) as well as metal complexes and metal-organiccompounds as an impurity within the active layer of an EL device. Someof the organic-based EL device layers may not contain dopants. The termEL device excludes incandescent lamps, fluorescent lamps, and electricarcs. EL devices can be categorized as high field EL devices or diodedevices and can further be categorized as area emitting EL devices andpoint source EL devices. Area emitting EL devices include high field ELdevices and area emitting OLEDs. Point source devices include inorganicLEDs and top-, bottom-, edge- or side-emitting OLED or LED devices. Highfield EL devices and applications are generally described in YoshimasaOno, Electroluminescent Displays, World Scientific Publishing Company(June 1995), D. R. Vij, Handbook of Electroluminescent Materials, Taylor& Francis (February 2004), and Seizo Miyata, Organic ElectroluminescentMaterials and Devices, CRC (July 1997), which are hereby incorporated byreference in their entirety. LED devices and applications are generallydescribed in E. Fred Schubert, Light Emitting Diodes, CambridgeUniversity Press (Jun. 9, 2003). OLED devices, materials, andapplications are generally described in Kraft et al., Angew. Chem. Int.Ed., 1998, 37, 402-428, and Z., Li and H. Meng, Organic Light-EmittingMaterials and Devices (Optical Science and Engineering Series), CRCTaylor & Francis (Sep. 12, 2006), which are hereby incorporated byreference in their entirety.

The light emitting elements can produce light in the visible range(e.g., 380 to 700 nm), the ultraviolet range (e.g., UVA: 315 to 400 nm;UVB: 280 to 315 nm), and/or near infrared light (e.g., 700 to 1000 nm).Visible light may correspond to a wavelength range of approximately 380to 700 nanometers (nm) and is usually described as a color range ofviolet through red. The human eye is not capable of seeing radiationwith wavelengths substantially outside this visible spectrum such as inthe ultraviolet or infrared range, but these wavelengths may be usefulfor applications other than lighting, such as phototherapy, security,disinfection, communications, plant growth, identification, orinspection applications. Furthermore, ultraviolet light may be downconverted by a luminescent material in the lamp. The visible spectrumfrom shortest to longest wavelength is generally described as violet(approximately 400 to 450 nm), blue (approximately 450 to 490 nm), green(approximately 490 to 560 nm), yellow (approximately 560 to 590 nm),orange (approximately 590 to 620 nm), and red (approximately 620 to 700nm). White light is a mixture of colors of the visible spectrum thatyields a human perception of substantially white light. The lightemitting elements can produce a colored light or a visuallysubstantially white light. Various light emitting elements can emitlight of a plurality of wavelengths and their emission peaks can be verybroad or narrow. In one example, the emission peaks may be greater than,less than, or equal to about 100 nm, 50 nm, 30 nm, 20 nm, 15 nm, 10 nm,5 nm, or 1 nm. In some examples, the entire wavelength emission rangemay be greater than, less than, or equal to about 500 nm, 400 nm, 300nm, 200 nm, 150 nm, 100 nm, 50 nm, 30 nm, 20 nm, 15 nm, 10 nm, 5 nm, or1 nm. Light emitting elements may be white LEDs or blue LEDs forexample. Furthermore, in a single lighting unit, light emitting elementsmay comprise a combination of colors such as red and white LEDs; red,green and blue LEDs; or red, blue, green, amber (yellow) and white LEDs;or any number of colors needed to best represent the range of spectralpower distributions and/or color qualities desired for the application.

A lamp 200 may include light emitting elements 210 that all emitwavelengths within the same range. Alternatively, light emittingelements that emit light in different wavelengths may be used. Forexample, a circuit board 220 may support one or more color of LEDs.

In some embodiments, it may be desirable for a lighting unit to includeboth white and red LEDs. In some embodiments, a combination of LEDs maybe used to form a white light. In some embodiments, one or more coolwhite LEDs and one or more red LEDs (e.g., having a wavelength in therange of about 620 to 700 nm) may be provided on a lighting unit. Inanother embodiment, one or more mint green or greenish white LEDs andone or more red LEDs (e.g., having a wavelength in the range of about600 to 700 nm) may be provided on a lighting unit. The LEDs havingdifferent wavelengths may be alternatingly positioned on the lightingunit. For example, white and red LEDS, or green and red LEDs may bealternatingly positioned along an edge of a circuit board. In otherembodiments, groups of white and red LEDS or groups of green and redLEDs may be alternatingly located along an edge of a circuit board. Insome embodiments, a lighting unit may include both blue and red LEDs, orblue, white, and red LEDs. In some embodiments, the proportion of whiteLEDs to red LEDs may be greater than, less than, or equal to about 20:1,15:1, 10:1, 7:1, 5:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:5, or 1:10. In someexamples, the proportion of white LEDs to red LEDs may fall betweenabout 5:1 and 1:1. The color and proportion of different groups of LEDsmay be configured to achieve a desired correlated color temperature(CCT), Duv, color rendering index (CRI), color quality scale (CQS), orother color specifications that may be required to meet Energy Starrequirements, for example. Different groups of LEDs may be drivenseparately to preserve color over lifetime and temperature. Furthermore,separately driving different groups of LEDs may allow color tuning anddimming features. Groups of light emitting elements may or may notcomprise light emitting elements of the same color.

There may be a desire to have a choice of the CCT that has achromaticity close to the black body locus in the range of 2700K to6500K. However, color temperatures beyond this range and chromaticitieswell above or below the black body locus can also be desirable.Similarly, the spectral power distribution (SPD) of a black bodyradiator, while in general of interest, is not the only SPD that isdesirable. One example is the SPD of daylight which is generally notshaped like a black body radiator nor is its chromaticity usuallylocated on the locus. Therefore its desirable for a light source to beable to accommodate a wide variation in both SPD and chromaticity as theapplication dictates while at the same time keeping light source tolight source variations at a minimum. While it is common for lightsources today to have a fixed CCT and SPD, it is also desirable to havea light source with an adjustable spectrum.

In some embodiments, the light emitting elements with various inputspectrums (different colors) can be component parts of the light source.These different colors could be visible in the light source unlessadditional optical elements or tools are employed. This conspicuousvariation of color may be desirable both for aesthetic reasons andefficiency reasons. Other examples of non-black body SPDs includeenhancing the blue portion of the spectrum to decrease melatonin andincrease wakefulness, enhancing the red portion of the spectrum to allowmelatonin to increase naturally to prepare for sleep in humans. Beyondpreparing humans for sleep or wakefulness, there are more generallydesigner spectrums with specific illumination goals that are ofcommercial interest. For example a spectrum that enhances color contrastfor retail product displays of all types or one optimized for productinspections of all types or one that improves worker productivity orstudent concentration levels. Other examples are spectrums that causefluorescence. These may be used, for example, to distinguish between abacterial, fungal, and other infections or medical conditions. These arejust some examples and should not limit the scope of designer spectrums.There are also lighting applications beyond human consumption. Forexample emphasizing the blue and red portions of the spectrum for plantsor the spectrum appropriate for health, reproduction, and growth inland, air, and water based animals. Thus, the spectrum for the lightemitting elements of the lamp can be selected to provide the desiredillumination for various applications.

The lamp may be color-tunable for different applications. In someinstances, lamps may be provided with different color spectrum emissionsfor different applications. In other instances, an individual lamp maybe adjustable between different color spectrum emissions for differentapplications. For example, a user may select a sleep mode to provide anillumination spectrum that gets a human prepared for sleep, or mayselect a waking mode to provide a different illumination spectrum thatkeeps a human awake. Similarly, the user may select between differentmodes for different applications such as a first illumination spectrumfor growing plants and a second illumination spectrum for interiorlighting for humans. An input region may be provided through which auser may select a mode for a lamp to operate. For example, a switch,button, touchscreen, lever, or other input mode may be provided throughwhich a user may select an operational mode for a lamp, which maydictate the color spectrum and/or intensity emitted by the lamp. Inputmay also be provided by a personal device, such as a phone or tablet.Input may also be provided by a spectral sensor located to receivedaylight.

A lamp 200 may include one or more circuit boards 220. One or more lightemitting elements 210 may be provided on the circuit board. The circuitboard may be a printed circuit board (PCB) or flex circuit. Any circuitboard material known in the art may be used. One, two or more lightemitting elements may be provided on a circuit board. Preferably, aplurality of light emitting elements are supported by a circuit board.The circuit board may also support and provide electrical connections toand/or between the light emitting elements. The circuit board mayprovide an electrical connection between one or more light emittingelements and a power source.

The circuit board may have any shape. For example, a circuit board maybe shaped as a rectangle, square, triangle, circle, ellipse, pentagon,hexagon, octagon, u-shaped strip, bent strip, or straight strip. In someembodiments, the circuit board may have a length that is substantiallylonger than any other dimension of the circuit board (e.g., width,height). For example, the circuit board may have a length to width ratiohaving a value that is greater than, less than, or equal to the ratiosdescribed for the body 110 of the lamp. In some embodiments, the circuitboard may have one or more sides. In some embodiments, the circuit boardmay have a straight side. A circuit board may be flat and/or thin. Acircuit board may be a rectangular strip.

Optionally, the circuit board may serve as a structural or supportelement. The circuit board may or may not serve as a heat dissipatingstructure. One or more side of the circuit board may contact the lightemitting elements, while an opposing side of the circuit board maycontact an optical element, such as a supporting optical element 230.Heat dissipation may occur through the side contacting the opticalelement (e.g., via conduction) and on the side contacting the lightemitting elements due to exposure to ambient air in the space 250.

The circuit board may have one, two or more light emitting elements on asurface of the circuit board. The light emitting elements may bepositioned on one side of the circuit board, on two side sides of thecircuit board, or any number of sides of the circuit board. The lightemitting elements may be disposed along the length of the circuit boardand may be spaced apart. The light emitting elements may form a rowextending along the length of the circuit board. The light emittingelements may have any arrangement, including those described elsewhereherein.

In some embodiments, the circuit board may form a rigid structure.Alternatively, the circuit board may form a flexible structure (e.g.,form a flexible PCB). The circuit board may be formed of a thermallyconductive material. For example, the circuit board may includealuminum, copper, gold, silver, brass, stainless steel, iron, titanium,nickel, or alloys or combinations thereof. The circuit board can beformed of any thermally conductive and/or heat dissipating materialdescribed elsewhere herein. In some examples the circuit board may be analuminum core circuit board, copper core circuit board, gold corecircuit board, silver core circuit board, brass core circuit board,steel-core circuit board, iron core circuit board, titanium core circuitboard, nickel core circuit board, alloys thereof, or thermal plasticcore circuit board, or have a thermally conductive core of any othermaterial described elsewhere herein. The circuit board may have athermal conductivity greater than, less than, or equal to about 0.1,0.5, 1, 2, 3, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, 175,200, 250, 300 W/mK.

A circuit board 220 may be flat. The circuit board may be an elongatedstrip. The circuit boards may be contact and lie flat against asupporting optical element 230. Alternatively, a circuit board may beangled relative to a supporting optical element. In some instances, nogap is provided between the circuit board and the supporting opticalelement.

In some embodiments, the circuit board may be opaque. Light from a lightemitting element may not substantially pass through the circuit board.Alternatively, the circuit board may be translucent or transparent(e.g., formed of glass or plastic). In some embodiments, the circuitboard may include one or more conductors. The conductors may betransparent or opaque. In some instances, the conductors of the circuitboard may be at least partially optically transmissive. The conductorsmay be formed from indium tin oxide.

The lamp 200 may have one or more optical element. For example, the lampmay have a supporting optical element 230 and/or a modifying opticalelement 240. The lamp may have any number of optical elements. Forexample, the lamp may have a first optical element and a second opticalelement. In some instances, the supporting optical element may be thefirst optical element while the modifying optical element may be thesecond optical element. Additional optical elements (e.g., third opticalelement, fourth optical element) may be provided.

The first optical element and the second optical element may or may nothave different properties. In some embodiments, multiple opticalelements may be provided which may share the same or similar features.Any description herein of the first optical element (e.g., supportingoptical element) may apply to the second optical element (e.g.,modifying optical element), and vice versa. In some embodiments, thelighting unit may have a first optical element as described hereinwithout having a second optical element. Alternatively, the lightingunit may have an optical element having characteristics of the secondoptical element described herein without having an optical element withcharacteristics of the first optical element. The lighting unit may haveany number of optical elements (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ormore optical elements).

The designation of first, second, third, etc. optical element does notnecessarily designate the order in which light is configured to bereceived by the optical elements. For instance, light from the lightemitting elements may be simultaneously received by the first and secondoptical elements, or light may be redirected by the second opticalelement to the first optical element.

The optical elements may be configured to provide a desired lightdistribution. For example, the shape, angle and optical properties offirst and second optical elements may be configured such that thestandalone lighting unit provides a “batwing” light distribution orother light distribution that is similar to that of a conventionalfluorescent tube mounted in a parabolic or other conventional troffer.Alternatively, the optical elements of the lighting unit may beconfigured such that when the lighting unit is mounted in a parabolictroffer, the light distribution profile matches that of a conventionalfluorescent tube mounted in parabolic or other conventional troffer.Alternatively, the optical elements may be configured to provide aconcentrated or narrow beam light distribution, or a lambertian emissionprofile. Optionally, less than lambertian or greater lambertiandistribution may be provided. The optical elements may be used toprovide wall-washing, or linear track lighting. The ability to tune thebeam angle and light distribution using the optical elements is anadvantageous feature of this design. Currently available fluorescenttube replacement products have light distribution profiles that do notmatch that of conventional fluorescent tubes mounted in conventionaltroffers. The light intensity provided by currently availablefluorescent tube replacement lamps at high angles is much less than thatof conventional fluorescent tubes in conventional troffers. Thus, forexample, to preserve the light distribution profile and uniformintensity across the illuminated floor space, additional troffers wouldneed to be installed if using currently available fluorescent tubereplacements lamps.

The systems and methods provided herein may be configured to provideuniform light. The configuration of the lighting unit may enable it todeliver light with little or no pixelation. The light illuminated in adirection of illumination may be continuous. The continuous light mayhave no pixelation or distinguishable subsections. Indirect lightingconfigurations as described and/or diffuse reflectors may be used toprovide the substantially unpixelated light. Light emitted by multiplelight emitting elements may be continuous over an extended region andare not divided into many small sub-sections or pixels that can beindependently activated to form an image. In some embodiments, lightdelivered to an illumination area may not vary substantially over thearea. The light intensity over an illumination area may optionally notvary substantially. For instance, the light intensity may not vary bymore than 1%, 3%, 5%, 7%, 10%, 12%, 15%, 20%, 25%, or 30% in a primarydirection of illumination. In some instances, the illumination may beless than or equal to 0.1, 0.5, 1, 2, 3, 4, or 5 JND (just noticeabledifference). Typically, professionals may be able to see about 1 JND,and 3 JND may be considered ok for the general public to not notice orcomplain. Over an area of 0.1 square meter, 0.5 square meter, 1 squaremeter, 2 square meters, 3 square meters, 5 square meters, or 10 squaremeters, the light intensity over any portion of the area may not varysubstantially. For instance, the light intensity may not vary by morethan 1%, 3%, 5%, 7%, 10%, 12%, 15%, 20%, 25%, or 30% over any of theareas described herein. For instance, the illumination may be less thanor equal to about 0.1, 0.5, 1, 2, or 3 JND over any of the areasdescribed herein. Any of the features and elements described herein maybe useful for providing non-pixelated light.

An optical element (e.g., first, second, third, etc. optical element)may be a reflector (e.g., diffuse or specular reflector), refractors(e.g., imaging, non-imaging, or Fresnel lens), diffractors (e.g.,including gratings and nano patterns), diffusers (e.g., including bulkand surface), filters (e.g., including high pass, low pass, and notch),and/or light guides (e.g., including flat and curved). An opticalelement may redirect, focus, diffuse, change the wavelength of, absorb,weaken, or have any other effect on light. Optionally, an opticalelement may be a clear window or transparent cover. A window can passvisible radiation with little attenuation but does not have opticallytransformative properties. Optical surfaces may or may not have antireflective coatings to increase efficiency. Optical surfaces may or maynot have luminescent materials disposed thereon, as discussed in greaterdetail elsewhere herein.

An optical element may include portions that may be used for lightreflectance, light refraction, and/or light diffraction. An opticalelement may have a diffuser, a lens, a mirror, optical coatings,dichroic coatings, grating, textured surface, photonic crystal, or amicrolens array. The optical element may be any reflective, refractive,or diffractive component, or any combination of reflective, refractive,or diffractive components. For instance, the optical element may be bothreflective and refractive.

A lighting unit may have at least one first optical element and at leastone second optical element. In some embodiments, a first optical element(e.g., supporting optical element) may be used to support a lightemitting element and/or a circuit board upon which the light emittingelement is disposed. The first optical element may be proximatelylocated relative to the light emitting elements. In other embodiments, afirst optical element may be located downward relative to the secondoptical element. For instance, the first optical element may be a loweroptical element. In some embodiments, emitted light may reach a firstoptical element after reaching a second optical element. The secondoptical element may direct light to the first optical element, and viceversa.

In some embodiments, a light emitting element may have primary optics,such as a portion of an LED package. A lighting unit may have one ormore secondary optics external to the light emitting element. Secondaryoptics may shape or modify the light output from a light emittingelement. Optionally, the first optical element (e.g., supporting opticalelement) is not a secondary optic and does not modify light. In someinstances, the secondary optical element is a secondary optic and doesmodify the light (e.g., redirect, diffuse, focus, or change thewavelength of the light). For instance, a light emitting element maycomprise a light emitting device and primary optics. For example, alight emitting diode package may comprise a chip and primary optics suchas a lens and/or reflectors within the package. There may be 0, 1, 2, 3,4, or more additional optical elements, which may serve as secondaryoptics. A first optical element, as described herein, may or may not bea secondary optic. Alternatively, no secondary optics may be provided inthe lighting unit. In some embodiments, light emitted from a lightemitting element does not pass through secondary optics.

The supporting optical element 230 may be a window. The supportingoptical element may be transparent. The window may be a clear pane. Thesupporting optical element may be substantially optically transmissive.Greater than 95%, 97%, 98%, 99%, 99.5%, 99.7%, 99.9%, 99.99% of thelight may pass through the supporting optical element. In someinstances, the supporting optical element does not substantially modifythe light that encounters and/or passes through the supporting opticalelement. Alternatively, the supporting optical element may modify thelight that it encounters and/or passes through the supporting opticalelement. For example, the supporting optical element may be a diffusewindow. The supporting optical element may be transparent. Thesupporting optical element may be an optical element of any kind asdescribed elsewhere herein. The supporting optical element may betranslucent or transparent. The first optical element may have any colorincluding, but not limited to, white, black, red, blue, green, oryellow.

The supporting optical element 230 may be a window at or near the bottomof a lamp 200. The supporting optical element may be positioned as thesurface of the lamp closest to the primary direction of illumination ofthe lamp (e.g., negative Z direction). Any description of bottom ordownward direction may also apply to the primary direction ofillumination of the lamp, whether the primary direction of theillumination of the lamp is in the direction of gravity or any otherdirection relative to gravity. The supporting optical element may bedisposed downward of the light emitting element. The supporting opticalelement may hold the weight of the light emitting element 210 and/orcircuit board 220.

The supporting optical element may have a flat surface. The supportingoptical element may have a surface contacting the circuit board and anopposing side. Both surfaces may be substantially flat and/or parallelto one another. The supporting optical element may extend along thelength of the lamp. The supporting optical element may have an elongatedshape. The supporting optical element may form a rectangular pane.Alternatively, other shapes may be provided as a pane with roundedcorners, an ellipse, a bent or curved shape, a U shape, a polygon, orother shapes. The ratio of the length of the supporting optical elementto the width of the supporting optical element may be high (e.g., any ofthe ratios of length to width provided elsewhere herein may apply). Thesupporting optical element may have a smooth surface. The supportingoptical element may be formed of, or may include, plastic, glass, metalor any other material. In one example, the supporting optical elementmay be formed of a plastic with a clear, specular or diffuse surface.The surface of the supporting optical element may be smooth, or may berough. The surface of the supporting optical element may be flat,curved, or have protruding or recessed features.

The supporting optical element 230 may be formed of a single integralpiece. For example, the optical element can be formed of a singletransparent or translucent material. Alternatively, the supportingoptical element may be formed of a plurality of pieces. A plurality ofpieces may be removably or permanently connected. In some instances thesupporting optical element may be formed via extrusion as a singleintegral piece. The supporting optical element may have homogenousmaterial properties. Alternatively, the supporting optical element mayhave heterogeneous material properties. For example, one or more portionof the supporting optical element may have a higher thermal conduction.The conductive portion 235 of the supporting optical element may beintegrally formed with the rest of the supporting optical element.Further characteristics of the supporting optical element and/or theconductive portion are discussed in greater detail elsewhere herein.

The lamp 200 may have one or more modifying optical elements 240. Insome embodiments, the modifying optical element 240 may distribute lightin a region or regions of desired illumination. The modifying opticalelement may receive light from one or more light emitting elements 210and redirect the light to a primary direction of illumination. The lightfrom the modifying optical element may pass through a supporting opticalelement 230. The light may or may not be further modified as it passesthrough the supporting optical element. For example, the light may bediffused or collimated as it passes through the supporting opticalelement. The modifying optical element may be an at least partiallyreflective reflector. The modifying optical element may be specular ordiffuse. The modifying optical element may scatter the light. Themodifying optical element may be a specular or diffuse at leastpartially reflective reflector.

The modifying optical element 240 may extend along the length of a lamp200. The modifying optical element may have the same length as asupporting optical element 230. When viewed from the Z direction, themodifying optical element may have substantially the same shape as thesupporting optical element. The modifying optical element may contact orbe coupled to the supporting optical element. In one example, thesupporting optical element may be inserted into a receiving portion 242of the modifying optical element. One or more groove or indentation maybe provided into which the edges of the supporting optical element maybe inserted. The receiving portion of the modifying optical element maywrap around a side of the supporting optical element and/or a bottomedge of the supporting optical element. The receiving portion mayoptionally contact a top surface of the supporting optical element, sidesurface of the supporting optical element, and bottom surface of thesupporting optical element.

The supporting optical element 230 may remain in the receiving portion242 of the modifying optical element 240 by mechanical connection. Insome instances, no adhesives or other connection mechanisms may berequired. Alternatively, the supporting optical element may connect tothe modifying optical element with aid of adhesives, soldering, welding,brazing, melting, fasteners, or other connection mechanisms. Thesupporting optical element may be removably/separably attached to themodifying optical element. This may provide an individual to access aninterior of the lamp. Alternatively the supporting optical element maybe permanently affixed to the modifying optical element.

The modifying optical element 240 may be substantially curved orsubstantially prismatic. The modifying optical element may contact thesupporting optical element at an end of the modifying optical element.The modifying optical element may substantially enclose the lamp. Forinstance, the modifying optical element may at least partially encloseone or more light emitting elements or a circuit board therein.

The modifying optical element may have a light reflecting component,light refracting component, light diffracting component, or acombination thereof. The optical element may have a diffuser, a lens, amirror, optical coatings, dichroic coatings, grating, textured surface,photonic crystal, or a microlens array, for example. The modifyingoptical element may have one or more features as previously describedfor the supporting optical element or any other optical element. Anydescription herein of the supporting optical element may also apply tothe modifying optical element, and vice versa. Furthermore, anydescription herein of the supporting optical element may apply to thesupporting optical element exclusively, the modifying optical elementexclusively or both the supporting and modifying optical elements, andvice versa.

The modifying optical element may or may not be fully or partiallyreflective. In some instances, the modifying optical element may becapable of reflecting at least 30%, 50%, 70%, 80%, 90%, 95%, 97%, 99%,99.5%, or 99.9% of the light incident thereon.

In another example, the modifying optical element may or may not permitthe transmission of light through the modifying optical element. In yetanother example, the modifying optical element may comprise cutouts orholes to allow light transmission through the modifying optical element.In some instances, the modifying optical element may be substantiallyopaque and may or may not include cutouts to permit the transmission oflight. Transparent or translucent portions may be provided on an opaquemodifying optical element. For example, one or more windows may beprovided as a modifying optical element. In a further example, one ormore at least partially translucent materials may be used to form themodifying optical element. The one or more translucent materials may beused to form the entirety of the modifying optical element or it may beused to form one or more pieces of the modifying optical element incombination with other materials suitable for forming an optical elementin accordance with the present invention. For instance, the modifyingoptical element may be formed from a translucent plastic. A translucentmodifying optical element may provide advantages as described elsewhereherein. For example, in a ceiling fluorescent tube replacementapplication in accordance with the present invention, light may shine upthrough the modifying optical element as well as down. A lamp thusconfigured may closer resemble the light distribution provided by somefluorescent tubes and may eliminate the “black hole” look of some typesof LED replacement lamps. The opacity, translucency and/or transparencyof the modifying optical element may be selected and/or distributed toform a desired optical effect.

A lamp may have any combination of optical elements with varying opticalproperties. For example, a lighting unit may have an opaque modifyingoptical element and a transparent supporting optical element, an opaquemodifying optical element and a translucent supporting optical element,a translucent modifying optical element and a transparent supportingoptical element, or a translucent modifying optical element and atranslucent supporting optical element. Any description of a translucentreflector may also apply to a transparent reflector. A lighting unit mayhave any combination of opaque, translucent, and/or transparentmodifying optical element, with any combination of opaque, translucent,and/or transparent supporting optical element. For example, a lightingunit may have a modifying optical element formed from pieces with opaqueand translucent properties and a supporting optical element formed frompieces with transparent and translucent properties.

The modifying optical element 240 may have a shape to provide a desiredoptical distribution. In one example, the modifying optical element mayhave a dip 244. The dip may bring a portion of the modifying opticalelement closer to the light emitting element. The dip may be providedlengthwise along the modifying optical element. The dip may extend alongthe entire length of the modifying optical element. The dip may overlieone or more light emitting elements 210 and/or circuit board 220. Thedip may be parallel to a row of one or more light emitting elementsand/or circuit board. In some embodiments, the modifying optical elementmay have a substantially rounded cross-section, around the lightemitting elements, with a dip coming in closer to the light emittingelements. The dip may form a sharp edge, or may form a rounded edge. Thecross-section of the modifying optical element with the dip may form adouble winged shape. The modifying optical element may be substantiallysymmetrical about a plane passing through the dip and parallel to the YZplane of the reference frame.

The shape of the modifying optical element can define the distributionof light from the lamp. Additionally, the curvature or mounting angle ofthe modifying optical element with respect to the position of the lightemitting elements can define the distribution of light from the lightingunit. In some embodiments, the modifying optical element may be shapedto reduce glare. In some embodiments, the modifying optical element maybe shaped to provide a diffuse light from the lighting unit. In anotherexample, the modifying optical element may be shaped to provide focusedlight from the lighting unit. The modifying optical element may beshaped to provide substantially collimated or uniform light from thelighting unit. The modifying optical element may cause light to divergeor be distributed over a wide area. Alternatively, the modifying opticalelement may cause light to converge or be distributed over a small area.The modifying optical element can cause light to travel in a parallelfashion to an area of distribution. The modifying optical element maydirect light in a primary direction, e.g., downwards, sideways, orupwards. In other embodiments, light may be distributed in manydirections without requiring a primary direction. For example, light maybe distributed downwards and sideways, downwards and upwards, upwardsand sideways, or any other combination of directions.

The modifying optical element may be curved. In one example, the secondoptical element may be curved about an axis extending lengthwise alongthe optical element. In some embodiments, the second optical element mayhave only one radius of curvature. Alternatively, the second opticalelement may have zero, one, two, three, or more radii of curvature. Aplurality of curvatures may or may not be provided in differentdirections. The second optical element may have a concave side and aconvex side. The concave side may be directed downwards in a primarydirection of illumination. The concave side may face a supportingoptical element. In some instances, a dip may be provided which maycause two concave portions to be formed. The two concave portions mayform two wings of the modifying optical element. A double-winged orarched structure may be provided by the modifying optical element. Thedouble-winged structure may be formed of two semi-cylindrical or curvedshapes.

In one example, the modifying optical element can be a reflectiveoptical element. The reflective optical element can be made of a plasticsupport with a thin, reflective metallic (e.g., aluminum, or other metaldescribed elsewhere herein) coating evaporated onto the surface that isthe side of the plastic support facing the supporting optical element.The curvature of the modifying optical element can be configured toprovide a broad distribution of light. Rather than a continuousreflective coating, the modifying optical element can comprisereflective regions on the interior surface of the modifying opticalelement. In other embodiments, the modifying optical element can beformed from a metal or metal alloy, such as those described elsewhereherein. The reflective regions can be made, for example, by polishingthe interior surface of the metallic modifying optical element. Thereflective regions can also be made by attaching a thin reflective filmvia the use of an adhesive or compression/tension, or any combination oftechniques described herein. Additionally, the shape or configuration ofthe modifying optical element can be changed to achieve a differentdistribution of light. For example, the radius of curvature of theoptical element may be reduced in order to achieve a narrowerdistribution of light. Light directed towards the optical element mayexperience multiple reflections off of the optical element before beingdirected towards another optical element and/or exiting the lamp.

The modifying optical element may have a smooth surface, or a surfacewith grating, diffusers, or other surface features. The modifyingoptical element may have a surface with any characteristic as describedelsewhere herein.

The modifying optical element 240 may optionally have a structuralstiffener 246. Alternatively, no structural stiffener may be required.In some instances, the structural stiffener may overlie a portion of themodifying optical element that dips downwards 244. In some instances,the structural stiffener may form a top/outer surface of the modifyingoptical element. The dip 244 may be provided on an interior portion ofthe modifying optical element and may not be exposed to the exterior ofthe lamp. The structural stiffener may have a curved surface. Thestructural stiffener may form an arch or semi-cylinder along the lengthof the modifying optical element. The structural stiffener may be asmooth, uninterrupted surface or may have one or more openings or holes.Alternatively, the structural stiffener may have a straight or bentsurface. The structural stiffener may connect a top surface of a firstwing 248 a with a top surface of a second wing 248 b of the modifyingoptical element. A space 260 may be provided between the structuralstiffener and the surfaces of the wings where the dip is located. Insome embodiments, directly over the light emitting elements, themodifying optical elements may provide two layers. For example, a firstinner layer may be provided where the dip is located to provide adesired optical distribution, and a second outer layer may be providedwhere the structural stiffener is located to provide structural supportfor the modifying optical element. The structural stiffener may aid inkeeping the modifying optical element's shape and preventing sagging orbending.

In some instances, the modifying optical element may be formed from asingle integral piece. The structural stiffener, wings, receivingportions, and/or dip portions may be integrally formed as a singlepiece. The modifying optical element may be formed via extrusion or anyother technique. The modifying optical element may be formed frommultiple parts permanently or separately attached to one another. Themodifying optical element may be formed from a plastic, glass, metal,any combination thereof, or any other material as described elsewhereherein.

In some implementations, the light emitting elements 210 might bepackaged white LEDs or chip-on-board (COB) arranged in a linear fashionthat point in a direction opposite to the primary direction ofillumination of the lamp. For example, if the lamp is primarilydirecting light downwards, the light emitting elements may be pointedupward. If the lamp is primarily directing light upwards, the lightemitting elements may be pointed downward. If the lamp is primarilydirectly light to a side, the light emitting elements may be pointed toan opposing side. The first optical element that the light encounterscould be the modifying optical element 240. In some instances, themodifying optical element may be a substantially hemisphericalreflector. The reflector may be diffuse, specular, or a director of somekind. The surface may efficiently redirect the light toward the primarydirection of illumination of the lamp. If the modifying optical elementis a diffuse reflector, it can minimize or reduce glare inherent in thewhite LEDs.

In one such configuration the LEDs (chips, packaged, or COB) can bemounted directly onto the supporting optical element 230, which may betransparent, diffuse, or have other optical properties. The LEDs may beelectrically interconnected with transparent conductors such as indiumtin oxide (ITO) or opaque conductors such as copper, tin, solder,nickel, iron, palladium, silver, or gold, in the form of wires or films(thick or thin). In one example, Noritake or other thick film paste maybe used. Optionally, no intermediary separate circuit board structuremay be required. In another case the packaged LEDs are mounted oncircuit board 220 that is then mounted on the supporting optical element(e.g., window). The shadow cast by the circuit board could be reduced orkept to a minimum for best efficiency and where possible eliminatedaltogether by direct mounting on the clear window. Since the heatdensity from the LEDs is low in this case and the surface area of thewindow is large in comparison, no further heat sink should be requiredfor many applications. If additional heat dissipation is needed, thematerial directly under the LEDs could be of a higher thermalconductivity 235 in conjunction with the other optical properties ofthis element. For example a co-extrusion process could combine differentmaterials, one with high thermal conductivity and another with goodoptical properties into a single element. The LEDs may be inapproximately the same plane as the supporting optical element and thesupporting optical element may act as a heat sink.

The shape of the roughly hemispherical modifying optical element 240 canbe further optimized to improve efficiency and shape light distributionas required for the application. One improvement would be a dip 244which may be a U- or V-shaped protrusion directly above the LEDs toredirect any light that may bounce directly back into the LEDs into amore favorable direction for illumination. By using other optical toolsmentioned above the light can be shaped in any distribution that wouldbe useful for a given application. In addition, the supporting opticalelement 230 (e.g., window) may be any of the optical tools mentionedabove to further shape or diffuse the light as may be required for theapplication.

Various optical element surfaces may mix the light from different colorLEDs if desired. One technique could be to extend the individual lightemitting elements in the long axis of the final light source to overlaptheir distributions. This would be useful in white-only applications toreduce pixelization or in multi-color applications to homogenize thecolors. An additional optical element could be added in-between theaforementioned two such as a lens or grating perpendicular to the longaxis of the final light source to accomplish this. The lens or gratingmay extend light emitting from one or more light emitting elements alongthe length of the lamp. In addition, this additional optical elementcould be any of the optical tools mentioned above and for purposes otherthan smoothing out the optical properties of individual light emittingelements (packaged LEDs, chip on board (COB), etc.) mentioned here.Another way to manage the lit appearance of multi color systems is touse multi-color phosphors or other down converter such as quantum dotsor multi-color filters on any of the optical elements in acomplimentary-color manner to the colors from the light emittingelements. Beyond the optical techniques already mentioned, simplypositioning the LED packages or LED chips in a COB closer together andor in multiple rows will improve both white pixelization and colornon-uniformity.

Light emitting elements may have a spectral power distribution. Thespectral power distribution may have an excess of energy in a particularcolor portion. For instance, there may be an excess of energy in thecyan portion of the spectrum compared to a thermal radiator. This mayenhance wakefulness in humans. The spectral power distribution may havea deficit of energy in a particular color portion. For instance, theremay be a deficit of energy in the cyan portion of the spectrum comparedto a thermal radiator to promote pre-sleep in humans.

The optical elements may be made of plastic, metal, or other materialswith suitable strength, thermal, optical, electrical isolation, and fireresistance as are required for the application. Common materials includemetals such as extruded aluminum and folded ferrous sheets, molded orextruded plastics such as acrylic, polycarbonate, and nylon in clear,semi transparent, white or otherwise opaque colors as required for theapplication. The surfaces may also have macro, micro, and nano featuresto redirect the light as required for the application.

In some embodiments, the light emitting elements 210 may be placed in alamp 200 so no direct line of sight is provided to the light emittingelements from the exterior of the lamp. In some instances, the lightemitting elements may be at least partially surrounded by a modifyingoptical element 240. The modifying optical element may optionally beopaque which may prevent a direct line of sight to the light emittingelements. In some instances, the light emitting elements may be disposedon a circuit board 220 which may prevent a direct line of sight to thelight emitting elements. In some instances, the direct line of sight toa light emitting surface of the light emitting element may be blocked.For example, if a light emitting element is emitting light from a topsurface, the view to the top surface of the light emitting element maybe blocked. Optionally, the rest of the light emitting element may ormay not be blocked. For example if a view of a top of the light emittingelement is blocked from outside the lamp, a view of the bottom of thelight emitting element may or may not be blocked. In some instances, asupporting optical element 230 may provide a view into the interior ofthe lamp. However, the other portions may or may not block a line ofsight from the exterior of the lamp to a light emitting element and/or alight emitting portion of the light emitting element. This may preventglare to a user viewing the lamp from any angle outside the lamp.

In some embodiments, light may be modified by an optical element atleast once prior to leaving the lamp. For instance, light may bereflected by the modifying optical element 240 prior to leaving thelamp. In some instances, the light may or may not pass through adiffuser prior to leaving the lamp. In some instances, a supportingoptical element 230 may or may not substantially modify the light as itpasses through the supporting optical element. The supporting opticalelement may be at least partially optically transmissive. In someembodiments, the supporting optical element may transmit at least 50%,70%, 80%, 90%, 95%, 97%, 99%, 99.5%, or 99.9% of the light thatinteracts with it.

Optionally, one or more surfaces of an optical element may have aluminescent material disposed thereon. For example, a luminescentmaterial can be disposed on a first optical element (e.g., supportingoptical element 230) without being disposed on a second optical element(e.g., modifying optical element 240), disposed on a second opticalelement without being disposed on a first optical element, or may bedisposed on both a first optical element and a second optical element.For example, a luminescent material may or may not be disposed on thesupporting optical element. The luminescent material may or may not bedisposed on a curved modifying optical element. The light emittingelements may be positioned such that light emitted from the lightemitting elements is at least partially directed towards the luminescentmaterial. In some embodiments, the luminescent material is not disposedon any optical element. In some instances, the lamp does not include anyluminescent material disposed on any surface.

A luminescent material may be disposed on a surface that is not lighttransmissive. In some embodiments, a luminescent material is notdisposed on a transparent or translucent surface. In some embodiments,light is not transmitted through the luminescent material.Alternatively, a luminescent material may be disposed on a lighttransmissive surface and light may travel through the luminescentmaterial.

A luminescent material may cover an entire surface or a portion of asurface. For example, the luminescent material may cover an entireunderside/interior surface of a modifying optical element. In anotherexample, the luminescent material may cover an entire portion of themodifying optical element that may receive light emitted by the lightemitting elements. In other instances, one or more parts of thedescribed surfaces may have a luminescent material disposed thereon. Thesame luminescent material may be provided for all portions of thelighting unit having a luminescent material disposed thereon.Alternatively, different portions of the lighting unit may havedifferent luminescent materials with different properties disposedthereon.

The luminescent material can comprise any material or combination ofmaterials that phosphoresces or fluoresces when excited by light fromthe light emitting elements. The luminescent material may also comprisethe binder, matrix or other material in which the phosphorescent orfluorescent material is dispersed. Any description of a luminescentmaterial may apply to a phosphor or fluorescent material, or anycombination thereof. The luminescent material may be a photoluminescentmaterial where absorption of photons may cause re-radiation of photons.The re-radiation may or may not be delayed. The emitted photons may ormay not be of lower energy than the absorbed photons. The luminescentmaterial can be an inorganic material, an organic material, or acombination of inorganic and organic materials. The luminescent materialcan be a quantum-dot based material or nanocrystal. In some embodiments,a luminescent material disposed on a highly reflective material asprovided by WhiteOptics LLC may be used.

Numerous luminescent material formulations can be used dependent on theexcitation spectra provided by the light emitting elements and theoutput light characteristics desired. For example, when the lightemitting elements provide an emission spectrum yielding white light witha high correlated color temperature, phosphors emitting light of a redand/or orange wavelength can be used to achieve lower/warmer correlatedcolor temperature white light and to improve the color rendering index.A luminescent material can be used to maintain or vary the wavelength oflight emitted by the lighting unit. For example, the wavelength of lightemitting from a light emitting element may be up-converted ordown-converted to a different wavelength by a luminescent material.Alternatively, the luminescent material need not alter the wavelength oflight emitted from the light emitting element. Developments inluminescent materials and applications are generally described in AdrianKitai, Luminescent Materials and Applications, Wiley (May 27, 2008) andShigeo Shionoya, William Yen, and Hajime Yamamoto, Phosphor Handbook,CRC Press 2nd edition (Dec. 1, 2006), which are hereby incorporated byreference in their entirety.

A remote luminescent material refers to a luminescent material that isnot inside or in physical contact with a light emitting element, such asan LED package. For example, a remote phosphor may be a phosphor thatdoes not directly contact a light emitting element. In one example, aremote luminescent material does not contact a primary optic of thelight emitting element. One advantage of using a remote luminescentmaterial is that color consistency of a lighting unit product can beenhanced through control of the formulation and deposition of theluminescent material. For instance, when LEDs are fabricated they arebinned according to their color characteristics. LEDs from differentbins can be used in production of lighting units without sacrificingproduct to product color consistency if the quantity and formulation ofthe luminescent material is adjusted depending upon the exact spectralpower density provided by LEDs.

Another advantage of using a remote luminescent material is that theremay be reduced thermal quenching of the luminescent material because itis physically displaced from the heat generating light emitting element,such as an LED package. Thus, the color of the light is more consistentwith lifetime and operating temperature. In comparison, in a luminairethat employs a typical warm white LED, the red and/or orange phosphormaterial is in direct contact with the LED package and will quenchrapidly as the LED is operated at higher temperature resulting in anoticeable shift in color point.

A further advantage of using a remote luminescent material is that toachieve a warmer color temperature, the selection of the luminescentmaterial is not limited only to materials that can operate well athigher temperatures. This can open up a range of materials that are notavailable to typical LED configurations.

The luminescent material can be disposed on a surface of the lightingunit, such as an optical element, in various ways, includingevaporation, spray deposition, sputtering, titration, baking, painting,printing, or other methods known in the art, for example. In someembodiments, the selected surface of the lighting unit may comprisegrooves, pockets, or knobs into or onto which the luminescent materialis disposed to control the optical distribution of the light emitted bythe luminescent material.

In some embodiments, the luminescent material is disposed on asupporting optical element, one or more portion of a circuit board, orany other portion of the lamp.

Optionally, no luminescent materials are provided on a lamp. In someembodiments, only a remote luminescent material may be provided on alighting unit. For instance, no luminescent material is contacting alight emitting element. Alternatively, a local luminescent material maycontact a light emitting element without a remote luminescent materialbeing provided on the lighting unit. Alternatively, both a local andremote luminescent material may be provided for the lighting unit.

In some embodiments, a light emitting element may be directed toward aremote luminescent material. Light may hit a remote luminescent materialdirectly from the source of light. In some embodiments, scattered lightmay also reach the remote luminescent material. Light may be directedupward to a remote luminescent material. An optical element may be usedto direct light to a remote luminescent material. In some embodiments,light may be directed in a different direction from a primary directionof illumination. For example, if a primary direction of illumination isdownward, light may be directed upwards, or upwards at an angle.

The lamp 200 may enclose an interior space 250. The one or more opticalelements 230, 240 may partially or completely surround the space. Insome instances, the space may be completely closed off. The space may ormay not be fluid tight (e.g., air tight, liquid tight, hermeticallysealed). In some instances, the interior space may contain air that maysubstantially remain within the lamp without requiring the lamp to befluid tight.

A second interior space 260 may be provided between surfaces of themodified optical element. The second interior space may be providedbetween a dip 244 and a structural stiffener 246. The second interiorspace may have air therein. The interior space may be substantiallyclosed off or enclosed. In some instances, the interior space may beopened at the ends of the modified optical element which may permit airtherein to flow. In some instances, air within the second interior spacemay substantially remain within the space without requiring the lamp tobe fluid tight.

In some instances, the interior space 250 and the second interior space260 are not substantially in fluid communication. The spaces may befluidically isolated from one another.

The interior space 250 may be illuminated by light from one or morelight emitting elements 210. The second interior space 260 may besubstantially dark. In some instances, the modifying optical element issubstantially opaque which may prevent light from the light emittingelements to reach the second interior space or the structural stiffener246. In some other embodiments, the modifying optical element may permitsome light to pass through, which may permit light to reach the secondinterior space and/or the structural stiffener.

In some embodiments, the lamp 200 may have a rounded side, and a flatside. In some embodiments, the flat side may face the direction ofprimary illumination by the lamp. The rounded side and the flat side maybe formed of optical elements, such as the modifying optical element 230and the supporting optical element 240 respectively. In someembodiments, the exterior surfaces of the optical elements may beexposed directly to ambient air. The exterior surfaces of the opticalelements may be provided without any fins, protrusions, or extra heatsinks provided thereon. The optical elements themselves may form as heatdissipating structures without needing any additional surface features.The optical elements may serve as a primary source of heat dissipationsuch that the majority of the heat is dissipated through the opticalelements.

FIGS. 3A-3B shows a light emitting element 310 and supporting structurein accordance with an embodiment of the invention. FIG. 3A shows anexample of a light emitting element on a supporting optical elementwithout an extra conductive feature, while FIG. 3B shows an example of alight emitting element on a supporting optical element having an extraconductive feature.

FIG. 3A shows a light emitting element 310 on a circuit board 320,contacting a supporting optical element 330.

The light emitting element may be attached to the circuit board. In someinstances, the circuit board may be opaque, translucent, or transparent.The LED may be affixed to the circuit board with aid of an adhesive orany other connection. In some instances, the width of the light emittingelement w_(L) may be less than the width of the circuit board w_(PCB).In other embodiments, w_(L)=w_(PCB) or w_(L)>w_(PCB).

In some embodiments, the circuit board may have a height h. The heightof the circuit board may have any value, such as a value greater than,less than, or equal to about 0.01 mm, 0.05 mm, 0.1 mm, 0.5 mm, 0.7 mm, 1mm, 1.2, mm, 1.5 mm, 1.7 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 5 mm, 7mm, or 1 cm. In some embodiments, the side of the circuit board, havingheight h may have a desired material property. For example, the side ofthe circuit board may be formed of a reflective material. In someinstances, the side of the circuit board may have a white color, or anyother color. In some instances, the side of the circuit board may beshiny and/or smooth. The surface of the side of the circuit board may becapable of reflecting substantially greater than about 50%, 70%, 80%,90%, 95%, 97%, 99%, 99.5%, or 99.9% of light incident thereon. Having areflective side of the circuit board may improve efficiency of the lamp.

The circuit board 320 may contact a supporting optical element 330. Insome instances, the circuit board may be provided on a flat,uninterrupted surface of the supporting optical element. In alternateembodiment, the light emitting element 310 may directly contact thesupporting optical element. In some instances, the circuit board may beattached to the supporting optical element with aid of an adhesive. Anadhesive tape may be used between the circuit board and supportingoptical element (e.g., double sided tape). In some instances, adhesivemay be pre-existing on the circuit board or the supporting opticalelement. Adhesive may be deposited via any technique (includingspraying, painting), known in the art on the circuit board or thesupporting optical element. In some embodiments, the adhesive may have ahigh thermal conductivity. The thermal conductivity of adhesive may beat least as great as that of the circuit board and/or the supportingoptical element.

The supporting optical element may have a thickness t. The supportingoptical element may have the same thickness across the entire supportingoptical element. Alternatively, the thickness may vary over thesupporting optical element. In some embodiments, the thickness of thesupporting optical element may be greater than, less than, and/or equalto about 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 1cm, 1.2 cm, 1.5 cm, 2 cm, or 3 cm.

The supporting optical element may be at least partially opticallytransmissive. The supporting optical element may permit at least 50%,70%, 80%, 90%, 95%, 97%, 99%, 99.5%, 99.9% of the light to pass through.The supporting optical element may be formed of a single integral piece.The light emitting elements and/or the circuit board may be disposed ona surface of the supporting optical element. The light emitting elementand/or circuit board may optionally not contact the walls (e.g., formedby a modifying optical element) of the lamp. In some embodiments, thelight emitting elements and/or circuit board may be provided on a centerportion of the supporting optical element and be substantiallyequidistant from the receiving portions of the modifying optical element(e.g., where the modifying optical element meets the supporting opticalelement) of the lamp.

Examples of materials that may be used to formulate any portion of thelamp may include, without limitation, polymers, such as acrylics,polyester (PES), polyethylene terephthalate (PET), polyethylene (PE),high-density polyethylene (HDPE), polyvinyl chloride (PVC),polyvinylidene chloride (PVDC), low-density polyethylene (LDPE),polypropylene (PP), polystyrene (PS), high impact polystyrene (HIPS),polyamides (PA) (Nylons), acrylonitrile butadiene styrene (ABS),polyethylene/Acrylonitrile Butadiene Styrene (PE/ABS), polycarbonate(PC), polycarbonate/Acrylonitrile Butadiene Styrene (PC/ABS),polyurethanes (PU), polyetheretherketone (PEEK), polymethyl methacrylate(PMMA), polytetrafluoroethylene (PTFE), or Urea-formaldehyde (UF).Materials may also include glass, resin, rubber, metals (aluminum,copper, brass, steel, iron, nickel, silver, gold, platinum, titanium) oralloys or combinations thereof. In some embodiments, coatings or filmsof one material may be provided on another. For example, a plastic maybe covered with a reflective metal.

The materials may have any material property. For example, they may havea thermal conductivity greater than, less than, and/or equal to about0.1, 0.3, 0.5, 1, 1.5, 2, 3, 5, 7, 10, 15, 20, 30, 40, 50, 60, 70, 80,90, 100, 120, 150, 175, 200, 250, 300, 400, or 500 W/mK. The thermalconductivity of a material may be in a range falling between any two ofthese values or other values.

Any discussion of the materials and material properties may apply to anycomponent of the lamp. For example, the materials described may be for amodifying optical element, a supporting optical element 330, circuitboard 320, or adhesive. In some embodiments, the components may have thesame or similar thermal conductivities as one another. In otherembodiments, they may have different thermal conductivities. The thermalconductivities of the components may be sufficient to dissipate heatfrom the light emitting elements 310 without sacrificing a high degreeof performance of the light emitting elements.

Heat from light emitting elements 310 may be conducted to a circuitboard 320, and to the supporting optical element 330. Heat may dissipatefrom the light emitting elements, circuit board, and the supportingoptical element to the ambient air. Thus, the supporting optical elementmay serve as both a structural support for the light emitting elements,and a heat dissipating component. The supporting optical element may beused as a primary heat dissipating component to the ambient environment.For example, heat generated by the light emitting elements may betransferred primarily through the supporting optical element. Themajority of the heat from the light emitting elements may be transferredto the environment through the supporting optical element. For instance,greater than 50%, 60%, 70%, 80%, 90%, 95%, or 99% of the heat may bedissipated through the supporting optical element. The supportingoptical element may also serve as a support that permits at leastpartial or substantially full optical transmission of light.

FIG. 3B shows a light emitting element 310 on a circuit board 320,contacting a supporting optical element 330 that has a conductiveportion 335. In some embodiments, a portion of the supporting opticalelement may have a higher thermal conductivity than other portions ofthe supporting optical element. In some embodiments, the higherconductivity portion may be formed from different material as the restof the supporting optical element. In some embodiments, the opticalproperties of the higher conductivity portion may be the same as therest of the supporting optical element, or may be different from therest of the supporting optical element. In one example, the higherconductivity portion may be opaque or translucent, while the rest of thesupporting optical element may be translucent or transparent. In anotherexample, both the higher conductivity portion and the rest of themodifying optical element may be clear. In some embodiments, the opticaltransmissivity of the higher conductivity portion may be lower than therest of the supporting optical element.

In some embodiments, a single higher conductivity portion 335 may beprovided in the supporting optical element 330. The higher conductivityportion may run along the length of the lamp. The higher conductivityportion may be a strip. The strip may be positioned beneath the lightemitting elements 310 and/or the circuit board 320. The strip may have awidth w_(C). In some embodiments, the width of the strip may be greaterthan a width w_(L) of a light emitting element and/or a width of acircuit board w_(PCB). Alternatively, the width of the strip may be lessthan or equal to width of a light emitting element and/or width of acircuit board. In some embodiments, the higher conductivity portion doesnot substantially interfere with the emission of light from the lamp.Optionally, the higher conductivity portion does not substantially blocklight transmitted through the supporting optical element.

The circuit board 320, which may be a PCB component, may be formed froma thermal ground plane. A thermal ground plane may be a thin sheet heatpipe where latent heat via phase transition from liquid to vapor mayincrease effective thermal conductivity to greater than about 50,000W/mK. This may effectively spread heat from light emitting elements 310to create an isothermal ground plane pinned to the saturationtemperature internal to the ground plane. The heat may then pass througha supporting optical element 330 by way of thermal conduction. Thehigher conductivity thermal ground plane may run along the length of thelamp. The addition of increased heat spreading from the light emittingelement 310 by way of a thermal ground plane formed into a printedcircuit board can be combined with an alternate heat conduction pathwayintegrally formed in the supporting optical element 330.

The higher conductivity portion may protrude from the surface of thesupporting optical element. The thickness t of the supporting opticalelement where the higher conductivity portion is provided may be greaterthan other portions of the supporting optical element. Alternatively,the higher conductivity portion may not extend out of the surface of thesupporting optical element may be provided beneath or integrated withina flat surface of the supporting optical element. The thickness of thesupporting optical element where the higher conductivity portion isprovided may be the same as other portions of the supporting opticalelement.

The higher conductivity portion may be formed as a single integral piecewith the rest of the supporting optical element. The higher conductivityportion may be extruded with the rest of the supporting optical element.In one example, the supporting optical element may be formed from aplastic, such as acrylic, and the higher conductivity portion may beformed from a higher conductivity plastic, or from a metal.

In some embodiments, a single higher conductivity portion is provided inthe supporting optical element. Alternatively, multiple higherconductivity portions may be provided.

Aspects of the invention may be directed to a light source (e.g., lamp)made up of light emitting elements attached to a PCB or flex circuit andin contact with a support structure and heat dissipating element anddirected toward at least one partially reflecting reflector and awayfrom the primary direction of the intended illumination. The supportstructure and heat dissipating element may be a supporting opticalelement.

The light emitting elements may include at least two colors or colortemperatures. The PCB or flex circuit may include a red down convertersuch as quantum dots to improve system conversion efficiency in the partof the spectrum. The light emitting elements may be chosen to emphasizethe blue portion of the spectrum while maintaining a white appearance todecrease the level of melatonin. The light emitting elements may bechosen to emphasize the red portion of the spectrum while maintaining awhite appearance to allow melatonin to build up naturally and preparehumans for sleep. The light emitting elements may be chosen to emphasizethe portion of the spectrum to improve the health and well being ofanimals.

The light source may include one or more additional optical elements. Atleast one additional optical element may extend the apparent size of thelight emitting elements in the long axis of the light source to reducepixelization or improve color mixing. In some embodiments, at least oneadditional optical element may modify the radiation pattern to anasymmetric pattern suitable for wall washing. The at least partiallyreflecting reflector may allow some transmission to provide anasymmetric up/down radiation pattern. An additional optical element maybe a support structure. An additional optical element may be a heatdissipating element.

In some embodiments, a cross-sectional width of the light source may behemispherical-like (i.e., not round). In some embodiments, across-sectional width of the light source may have two distinct widthsthe larger of the two improves optical efficiency and the smaller of thetwo provides mechanical and electrical compatibility with T8 sizefluorescent lamps. The light source may have a size range from a T5 to aT50 (i.e., have a diameter falling within a range of ⅝″ to 50/8″).

A light source may be made up of light emitting elements attached to anoptical element that acts as a heat sink.

A light source may be made up of multi color or multi color temperaturelight emitting elements attached to a PCB or flex circuit and in contactwith a support structure and heat dissipating element and directedtoward at least one partially reflecting reflector and away from theprimary direction of the intended illumination. The light source may useone or more phosphors or other down converter or one or more filters onone or more of the optical elements in a complimentary manner to themulti color or color temperature light emitting elements to homogenizethe lit appearance of the light source. The down converter may be localto the light emitting element and/or may contact the light emittingelement. In other instances, the down converter may be remote to thelight emitting element. For instance, a wavelength down converter may beon a surface that does not contact the light emitting element, or asurface that is some distance away from the light emitting element.

It should be understood from the foregoing that, while particularimplementations have been illustrated and described, variousmodifications can be made thereto and are contemplated herein. It isalso not intended that the invention be limited by the specific examplesprovided within the specification. While the invention has beendescribed with reference to the aforementioned specification, thedescriptions and illustrations of the preferable embodiments herein arenot meant to be construed in a limiting sense. Furthermore, it shall beunderstood that all aspects of the invention are not limited to thespecific depictions, configurations or relative proportions set forthherein which depend upon a variety of conditions and variables. Variousmodifications in form and detail of the embodiments of the inventionwill be apparent to a person skilled in the art. It is thereforecontemplated that the invention shall also cover any such modifications,variations and equivalents.

What is claimed is:
 1. A lamp comprising: one or more light emittingelements emitting light primarily in a direction that is different froma primary direction of illumination of the lamp; a circuit board uponwhich the one or more light emitting elements are disposed; and asupporting optical element formed from an at least partially opticallytransmissive material supporting the circuit board.
 2. The lamp of claim1, further comprising a modifying optical element configured to redirectlight from the one or more light emitting elements to primary directionof illumination.
 3. The lamp of claim 1 further comprising an additionaloptical element including a lens or grating that extends the lightemitted from the one or more light emitting elements along a length ofthe lamp.
 4. The lamp of claim 1, wherein the circuit board is formed ofan at least partially optically transmissive material selected fromplastic or glass.
 5. The lamp of claim 4, wherein the circuit boardcomprises transparent conductors.
 6. The lamp of claim 1, wherein thecircuit board and the supporting optical element are integrally formed.7. The lamp of claim 2, wherein the modifying optical element is adiffuse or specular reflector that is at least partially reflective. 8.The lamp of claim 2, wherein the modifying optical element has a firstwing and a second wing and a structural stiffener connecting the wingssuch that a space is formed between the structural stiffener and thefirst wing and the second wing.
 9. The lamp of claim 2, wherein thesupporting optical element is substantially flat and the modifyingoptical element is substantially curved and contacts the supportingoptical element, thereby at least partially enclosing the lamp.
 10. Thelamp of claim 1, further comprising at least one wavelength downconverter configured to interact with the light emitted by the one ormore light emitting elements.
 11. The lamp of claim 10, wherein the atleast one wavelength down converter is a phosphor or a quantum dot. 12.The lamp of claim 10, wherein the at least one wavelength down converteris located remotely from the one or more light emitting elements. 13.The lamp of claim 1, further comprising a U-shaped or V-shapedprotrusion above the light emitting elements configured to direct lightaway from the light emitting elements.
 14. A lamp comprising: one ormore light emitting elements emitting light primarily in a directionthat is different from a primary direction of illumination of the lamp;a circuit board upon which the one or more light emitting elements aredisposed; and a modifying optical element configured to redirect lightfrom the one or more light emitting elements to primary direction ofillumination, wherein the redirected light is non-pixelated.
 15. Thelamp of claim 14, wherein the non-pixelated light is distributed with acontinuous intensity and are not divided into pixels with a less thanone justice noticeable difference (JND) in the primary direction ofillumination.
 16. The lamp of claim 14, wherein the intensity of lightdistributed in the primary direction of illumination is lambertian. 17.The lamp of claim 14, wherein the modifying optical element is a diffuseor specular reflector that is at least partially reflective.
 18. Amethod of providing illumination comprising: emitting light, from one ormore light emitting elements of a lamp, primarily in a direction that isdifferent from a primary direction of illumination of the lamp;electrically connecting the one or more light emitting elements to apower source using a circuit board upon which the one or more lightemitting elements are disposed; and supporting the circuit board using asupporting element; and transferring heat from the one or more lightemitting elements of the lamp to the ambient environment primarilythrough the supporting element.
 19. The method of claim 15 wherein thesupporting element is formed from an at least partially opticallytransmissive material.
 20. The method of claim 15, further comprisingaltering the light from the one or more light emitting elements to bedistributed in the primary direction of illumination using a modifyingoptical element.